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There are many reasons to promote good welfare in laboratory-housed animals. The first of these is often ethical; a concern for the “well-being” or welfare of animals has been a predominant concern throughout history. In the situations in which animals are used for human benefit, such as food production, sport and laboratories, there is a particular ethical concern that the costs to the animals be minimised and welfare maximised.

attitudes to animals

There are many ethical approaches to the use of animals in scientific research. There are varying approaches taken to assessing the harms and benefits, caused by the varying value attached to human gain and animal suffering [1] with a utilitarian approach often taken in the use of animals in research.

The utilitarian approach is often adopted in the assessment of costs, or harms, and benefits in animal research [2]. The principle of utilitarianism is that the benefit of an action (its utility) is measured in the ‘happiness’ it provides to living beings [3]. The underlying question which drives ethical debate in the use of animals for scientific purposes is are the harms caused to animals justified by the benefits to humans?

The evaluation of harms and benefits has been incorporated into frameworks and legislation (see Legislation), from A(SP)A (1986) [7] to European Union Directive 2010/63, which introduced Animal Welfare and Ethical Review (AWERB) panels for this explicit purpose. In the UK, the Animal Procedures Committee’s Review of the cost-benefit assessment in the use of animals in research (Animal Procedures Committee, 2003)[4] provides guidance in addition to A(SP)A. The purpose of bringing this analysis into legislation is to ensure there is always a reasoned, justified case for the use of animals in harmful scientific procedures and to base decision-making not on feeling, but on considerations of ethics and science, both animal welfare science, and the best models of biomedical science.

The history and application of the principle of humane science

The three ‘R’ principles of humane science using animals which have become central to legal and ethical frameworks were first described by William Russell and Rex Burch in their book “The Principles of Humane Experimental Technique”, first published in 1959 [6]. The 3Rs were first presented at a Universities Federation for Animal Welfare symposium in 1957, following an investigation by Russell and Burch into the ethics of the use of animals in research and have become central guiding principles in humane animal research.

In contrast to other viewpoints which considered animal welfare to be complimentary to or sometimes in conflict with good science, they postulated that animal welfare was central to good science, and does not require compromise in scientific aims. Although this is a less contentious view now, it was much more controversial at the time. These principles were central to informing the reduction of animal use and improvements in animals’ welfare at a time in which there was much investment and many advances in the biomedical sciences [5].

“If we are to use a criterion for choosing experiments to perform, the criterion of humanity is the best we could possibly invent... The greatest scientific experiments have always been the most humane and most aesthetically attractive, conveying that sense of beauty which is the essence of science at its most successful ” Russell and Burch, 1959.

The 3Rs

The use of the 3Rs has evolved as scientific knowledge has developed, and the definitions for the 3Rs have changed from Russell and Burch’s original definitions. The UK’s NC3Rs uses the following definitions for the 3Rs:
The 3R principles underpin current within the EU and UK ( e.g. A(SP)A (Home Office, 1986), legislation used by the Home Office to regulate research using animals in Great Britain and European Directive 2010/63/EU (European Union, 2010) [8], on the protection of animals used for scientific purposes).
Researchers have the responsibility to demonstrate that there is no alternative to animal use for their study (Replacement), that the number of animals has been minimised through good experimental design (Reduction) and that costs (harms) to the animals are minimised.
In practice, the 3Rs are critical guiding principles to ensure we meet our ethical and scientific obligations in the use of animals for scientific purposes. This is especially true given the implications for the validity of the science as good provisioning of factors which promote good welfare affect study outcomes (see Dogs and Science). More than that, applying the three ‘R’ principles is vital to satisfy our moral obligations to reduce suffering. Working definitions of the 3Rs can be found on the website of the National Centre for the 3Rs.

Replacement

Some of the key differences in definitions result from advances in research methods which couldn’t have been foreseen by Russell and Burch. These include the use of computer modelling and in vitro methods as suitable Replacement methods, and while Russell and Burch’s definition prohibits Replacement via the use of conscious living vertebrates, the NC3Rs definition recognises the place of non-protected animals and human volunteers in Replacement methods, for example using less sentient species.

Reduction

The definition of Reduction has also broadened to include not only using fewer animals in absolute terms, but gaining more information from the same number of animals, decreasing acceleration in animal use as scientific knowledge advances. This pledge to Reduce animal use in the UK has resulted in moderate increases in animal numbers at a time when scientific research is accelerating.

Refinement

The greatest difference, however, is in the definition of Refinement, applied simply to the harms caused by procedures by Russell and Burch. This latest definition acknowledges that Refinement should be applied to many aspects of the animals’ experiences, and encompasses not only reducing negative welfare but also increase positive welfare.
The definition of Refinement has continued to evolve from Russell and Burch’s original
concept to “reduce to an absolute minimum the amount of stress imposed on those animals that are still used”(Russell & Burch, 1959, p. 64) [6].

While Russell and Burch’s original use of the term “Refinement” was applied to improvements in procedures and husbandry, and only considered decreasing negative welfare, Buchanan-Smith et al. [9] proposed a new definition, taking into account all experiences throughout the life of an animal from birth to death in a more holistic approach. Other relevant aspects of an animal’s life can include breeding and early rearing environment, weaning, sourcing and transport, housing, and the eventual endpoint for the animals. Where these have a negative impact on welfare, they are known as contingent harms, Refinement ensures that all aspects of the animals’ lifetime experience are taken into account. Most importantly this recognises that welfare may not only be diminished by direct harms such as scientific procedures.

Furthermore, it is critical that all animals are included in the definition of Refinement; it is not only the animals destined for use in procedures which may suffer negative welfare, and Refinement should also be applied to founder animals in breeding colonies, thus encompassing all aspects of animal use within scientific research (Buchanan-Smith et al., 2005). Many of the aspects of the laboratory environment with the potential to cause distress to dogs are not regulated procedures and to omit these from the sphere of Refinement would be negligent. Poor welfare in the breeding facility would likely predispose the dogs to poor welfare in later life and influence coping styles, and so the holistic nature of Refinement is apparent.

Stakeholders

There are many stakeholders in the promotion of humane animal research. Pharmaceutical and contract research organisations have a vested interest in improving the welfare of animals used in research, not only because of the intrinsic value of good welfare, but to improve the quality of data obtained from animal use and to make research more efficient.

One of the greatest stakeholders in good quality animal research is the public. Much animal research is conducted for the benefit of the public, through medical advances, discovery of new disease treatments or protection through the safety testing of new chemicals. In many countries, government bodies fund medical research which invariably requires the use of animals. That means that the public often funds and benefits from the use of animals in research. It’s important, therefore, that members of the public are educated and engaged in the conduct of animal research. The public continue to show a vested interest in the welfare of animals used in science and the success of research. Recently, patient groups have become more involved in LAS. The general public have particular concerns about the use of dogs, hence their special protection.

In the UK, Government bodies invested in animal research include NC3Rs, the Home Office's Animals in Science Regulation Unit (ASRU) and Medicines and Healthcare products Regulatory Agency (MHRA). The Government has a commitment to Reducing the numbers of animals used in scientific procedures, while also supporting scientific progress. Refinement of procedures and improvement of data quality can increase statistical power and Reduce animal numbers. The Government set up and contributes to funding the NC3Rs with the remit of promoting the 3Rs in UK-based research.